Battery to the future – new innovations in electricity storage

Progress and innovation in electricity storage looks set to increase in 2015 as a range of new technologies at the domestic and grid scale come on stream.

Electricity may be the most flexible form of energy, but beyond the small-scale, it cannot be stored. Supply must always match demand and ‘surplus’ electricity be converted into some form of potential energy (e.g. in chemical battery) until it is needed.

Electricity storage is often discussed in the context of renewable energy, but it’s already used on a national scale to deal with the daily fluctuations in our demand for power. On a typical weekday morning the average demand for electricity in the UK climbs by roughly 13GW between 6.30am and 8.30am.

Belectric 3MW block hybrid

In an ideal world electricity generators would be asked to meet a constant and smooth demand for electricity so they could select the cheapest means of generating power without having to adjust to the daily peaks and troughs produced by the combined actions of millions of users. In an ideal world.

As more renewable energy comes onto the UK and European supply grids it creates variations in the supply of electricity, overlaid on existing variations in demand. Some of this balances out but the ability to smooth out renewable electricity supply is focusing the attention of engineers and investors alike. By generating electricity when demand is low and supplying it when demand is high, suppliers can make money.

Now a new storage facility in Germany looks set to allow a solar power plant to do just that. The system, in effect a giant lead acid battery, has a capacity of 2MWh and is intended to be linked to both renewable energy and conventional power plants and stabilise and smooth the energy grid.

Belectric’s energy buffer unit for the ‘storage’ of electricity and grid stabilisation

The Belectric unit is just one of a number of new ideas which are being developed and trialled. In the UK green energy providers such as Ecotricity are developing ‘black box’ home energy storage devices to smooth out peaks in demand and enable homes with PV systems to use a higher proportion of the energy they generate. They may also be used to ‘store’ cheap rate night electricity for using during the day when prices are higher.

The greatest potential for electricity storage could come as a fringe benefit of electric vehicles. Most cars spend most of the time parked rather than moving. In Sustainable Energy Without the Hot Air, David MacKay makes the case for using a national fleet of (30m) electric vehicles to smooth out the peaks and troughs from the national fleet of wind turbines.

Smart charging electric vehicles could help to smooth out peaks & troughs in electricity demand

Using smart chargers the vehicles would charge up, when parked at times of surplus demand and supply electricity back to the grid at times of peak demand. Drivers would set the limits on now much charge they needed and how much they will provide and be paid accordingly.

This may be some time off, but domestic and building scale storage is likely to appear in 2015.